21192541 has 2 divisors, whose sum is σ = 21192542. Its totient is φ = 21192540.

The previous prime is 21192529. The next prime is 21192547. The reversal of 21192541 is 14529112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19802500 + 1390041 = 4450^2 + 1179^2 .

It is a cyclic number.

It is not a de Polignac number, because 21192541 - 2⁹ = 21192029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21192547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10596270 + 10596271.

It is an arithmetic number, because the mean of its divisors is an integer number (10596271).

Almost surely, 2^21192541 is an apocalyptic number.

It is an amenable number.

21192541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21192541 is an equidigital number, since it uses as much as digits as its factorization.

21192541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 25.

The square root of 21192541 is about 4603.5357063892. The cubic root of 21192541 is about 276.7330378982.

The spelling of 21192541 in words is "twenty-one million, one hundred ninety-two thousand, five hundred forty-one".